Among typical types of electric motor, there is a motor which includes a commutator having a plurality of segments, and a brush. The brush is brought into sliding contact with each segment of the commutator.
It is necessary for the electric motor as described above to reduce a dimension of a bracket in a height direction for achieving a reduction in size or weight of the electric motor. In order to reduce the dimension of the bracket in the height direction, for example, there is a method of reducing the thickness of the bracket. However, if the thickness of the bracket is reduced, the stiffness of the bracket is lowered. Consequently, there is a possibility that a bearing held by the bracket vibrates due to vibrations of the electric motor. The vibrating bearing causes the runout of a rotational shaft, so that the commutator fixed to the rotational shaft wobbles. As a result, the commutator is separated from the brush in some cases, which results in unstable conduction between the commutator and the brush. Thus, there arises a problem in that sparking occurs between the commutator and the brush. For this reason, there arises a problem in that the lifetime of the electric motor becomes short.